And they are doing this in a peer reviewed journal:

A decade after wisps of anthrax sent through the mail killed 5 people, sickened 17 others and terrorized the nation, biologists and chemists still disagree on whether federal investigators got the right man and whether the F.B.I.’s long inquiry brushed aside important clues.

Now, three scientists argue that distinctive chemicals found in the dried anthrax spores — including the unexpected presence of tin — point to a high degree of manufacturing skill, contrary to federal reassurances that the attack germs were unsophisticated. The scientists make their case in a coming issue of the Journal of Bioterrorism & Biodefense.

F.B.I. documents reviewed by The New York Times show that bureau scientists focused on tin early in their eight-year investigation, calling it an “element of interest” and a potentially critical clue to the criminal case. They later dropped their lengthy inquiry, never mentioned tin publicly and never offered any detailed account of how they thought the powder had been made.

The new paper raises the prospect — for the first time in a serious scientific forum — that the Army biodefense expert identified by the F.B.I. as the perpetrator, Bruce E. Ivins, had help in obtaining his germ weapons or conceivably was innocent of the crime.

Both the chairwoman of a National Academy of Science panel that spent a year and a half reviewing the F.B.I.’s scientific work and the director of a new review by the Government Accountability Office said the paper raised important questions that should be addressed.

…………

In its report last February, the National Academy of Sciences panel sharply criticized some of the F.B.I.’s scientific work, saying the genetic link between the attack anthrax and a supply in Dr. Ivins’s lab was “not as conclusive” as the bureau asserted.

If the authors of the new paper are correct about the silicon-tin coating, it appears likely that Dr. Ivins could not have made the anthrax powder alone with the equipment he possessed, as the F.B.I. maintains. That would mean either that he got the powder from elsewhere or that he was not the perpetrator.

The FBI hasn’t covered itself in glory,

Their behavior towards their first “person of interest”, Steven Hatfill, as well as their behavior toward Bruce Ivins, seemed to be geared more toward driving their subjects to self destruction than to any finding of fact. (They went after Ivins’ counselor, for example).

The bottom line here is that there is a lot of highly classified information that was not subject to review for this article, and a continued insistence on the part of the DoJ merely serves to reinforce the people who believe that the FBI did not find the right guy.